Reverse-gear actuator



Oct. 9, 1928.

R. L. DOOLITTLE ET AL REVERSE GEAR ACTUATOR Filed July 1, 1926 3 Sheets-Sheet 1 Qwmwtow ZZaZar/Zflaa /4ZZZ Oct. 9, 1928.

REVERSE GEAR ACTUATOR 5 Sheets-Sheet Filed July 1, 1926 MW N. k. r m w Z a M y 3 a m m a I n m. I 4 Q 1 \A MW o r% WI u m? w SM i \1l.. MW MM. 4 w x \Q M \h. My N QM. 0 MM \n W mm w HH t QM m e l aten'ted @ct. 9, 192-8 UNITED STATESPATENT orricn ROBERT L. Doom'r'rnE AND WILLIAM c. HUNTER, or MONTGOMERY, ALABAMA.

REVERSE-GEAR ACTUATOR.

Applicationfiled July 1, 1926. Serial No. 119,915,

The invention relates to improvements in fluid controlled mechanisms including an assemblage of cylinders and pistons fer shifting some movable part of another mechanism and while the principal application of the invention is for the purpose of controlling a locomotive reverse, gear, it is by no means restricted to this field of use,

One object of the invention is to provide an improved mechanism in which novel provision is made for obtaining the necessary movement of the part to'be shifted without the necessity of moving the pistons the same distance, thereby effecting a saving in fluid pressure and greatly diminishing the wear on cylinders, pistons and piston packings, over that which obtains when the pistons must travel a greater distance, and the invention also permits the mechanism to be manufactured in a much smaller size than the class set forth in which the movable parts are so encased as to be effectively protected against weather conditions, grit, dust and other fore gn matter.

A still further aim, is to make novel provision whereby the pistons may be held against movement under the unbalanced fiuid pressure which would exist in the cylinders and could not becontrolled by the engineer in case of a break or severe leakage in either of the fluid supply pipes leading to the cylinders, hold the pistons, the valve gear would be shifted to one extreme or the other, and if shifted to reverse position, the'locomotive could not be driven forwardly vice- Versa.

Figure 1 is a side elevation of a fluid controlled mechanism constructed in accordance with our invention and designed primarily lustrating the manner in which one of the pistons may be held against movement toward the outer end of its cylinder.

Were it not possible to so In thedrawings above briefly described,

the numerals 5 designate two longitudinally spaced cylinders. connected by a cross head guide 6, which guide is preferably tubular and may be either separate from or integral with the inner ends of said cylinders, and

the relativeidiameters of cylinders and guide as shown in Figure 2, preferably though not necessarily exist. The cyhnders 5 are pro vided with cylinder heads 7 at their outer ends, detachably securedv in place by any desired means such as the screws 8. These cylinder heads preferably carry pet-cocks 9, and for a purpose to appear, each of said cylinder heads is formed with a central opening 10 normally closed by a screw plug A cross head-12 is slidably mounted in the guide 6 and is rigidly secured to a pair of piston rods 13'whose outer ends are secured to pistons 1 1- slidably received in the cylinders 5, each piston hassuitable packing, such asa cup leather 15. By preference,

the pistons are detachably mounted upon the piston rods 13, by any suitable'ineans such as the screws 16." v

In the present disclosure, the cross head 12 is in the'form of an elongated hollow cylinder, the end walls of'said cylinder having bosses 17 apertured to receive the piston "rod 13, which rod may be secured in the bossesby said screws or other'desired means 16, Two parallel, spaced webs orwalls 19 are disposed withinthe'hollow cross head 12 and are preferably integral with the cylindrical walland thel' end walls thereof,

and said cylindrical wall is formed with upper and lower longitudinal slots 20 and 21 which, communicate with the, space between said webs or walls 19. These slots 20 and 21 register with other slots 22 and 23 formed longitudinally in the cross head guide 6,3

' 'Avertical lever 24 passes through the slots 2022 and 21'23' and through the space between the webs or walls 19, the ends of said lever projecting respectively above and below the guidefi. Substantially at its center, this lever is pivoted .to the webs or the like 19 by a bolt 25, and the cylindrical wall of the cross head 12 is formed with openings 26 giving access to this bolt when the cross heads in position to bring said openings 26 into registrlationwith otheropenings 27 in the guide 6. This arrangement of openings is only illustrative of one wayin which the pivot 25 may be made accessible, permitting disconnection of the lever 2st from the cross head and removal of; said cross head in case any repairs or replacements are necessary.

when the pivot 25 is withdrawn, and lover 2-1 is disconnected from other parts which will hereinafter be described, said over may be upwardly withdrawn from theremaindcr of the mechanism.

The upper end of lever 2a is pivoted at 28 to one end of a substantially horizontal link 29, said link being preferably forked at to receive said upper end of lever 2%. The end of this link opposite the fork, is pivoted at 31 upon one end of the cross head guide 6, the latter being provided with upstanding lugs 32, in the present disclosure, to which the pivot connects said link.

The lower end of lever 24 is pivoted at 33 to one end of the link 34L, and the other end of this link is pivoted at 35 to a member 36 to be shifted from one position to another. In the present showing, this member 36 may be considered as an adjusting device for a locomotive reverse gear.

By the general construction and arrangement of parts above described, it will be seen that a rather slight piston travel and consequent travel of the cross head 12, will move the end of the lever 2 L carrying the pivot 33, a relatively slight amount. Thus, the member may be shifted to the re quired extent without the necessity of having the pistonand crosshead moved to the same extent. Thus, saving in fluid pressure utilized to shift the piston is effected. Also, wear upon pistons, cylinders, cross head, cross head guide and piston packings, is reduced to the minimum, providing a mechanism of exceptionally long life. It will also be observed that the general construction is such that practically all working parts are effectively protected against weather conditions, grit, etc. in this connection, attention may be directed to the fact that a protecting covering 8'? is preferably employed for the link 9, the upper end of the lever 24 and the pivots 28 and 31. This covering may be provided with any adequate means 38 permitting lubrication of the pivots 28 and 31 and if desired, other lubrieating means (not shown) could be provided to be supplied with oil upon removal. of

the means 38.

.shown n, said arm being pivoted at 42 to the upper end of a floating lever 43. The low *1 end of this lever is fulcrumed at 44 to a link. 15, which link pivoted at 4.6 to the lower end of the lever 24-. Between its ends, the lever a3 is pivoted, at 47, to an adjusting rod l8 which is appropriately connected with a reverse lever 49, the latter having appropriate means 50 by which it maybe locked in one position or .another. By means of the lever 49, the valve 40 may be setto direct fluid pressure to either of the cylinders 5, according to the direction in which the member 36 is to be moved, and when the desired movement of this member has taken place, the parts as, it, 4:3, 4-2and ll, will have restored the valve lOto its closet. position. This controlling means for the valve 4:0 is similar to others heretofore devised and for it, no claim is made in the present application.

In case of breakage orsevere leakage in one or the other of the pipes 39, we provide means insertible through the openings 10,

claimed, variations may be made.

li loreover, it is to be understood that such terms as vertical, upper and lower? are relative rather than limiting.

We claim 1. A. fluid controlled mechanism comprising two cylinders spaced apart in axial alignment, a cross head guide between said cylinders, a cross head slidably engaged with said guide and formed with an opening leading from one of its sides to its opposite side, a lever passing through said opening of the cross head and projecting in opposite directions from the latter, a link disposed longitudinally of said guide and pivoted at one of its ends to one end of said lever, means pivotally connecting the other end of said link to a part which is stationary with respect to the aforesaid cylinders, means for connecting the other end of said lever with a part to be shifted, a pivotal connection between said cross head and the intermediate portion of said lever,pistons in said cylinders having rods connected with said crosshead, and means for conducting fluid under pressure to the outer ends of said cylinders. I v

2. A luid-controlled mechanism compris in two spaced axially alined cylinders havmg removable heads at their outer ends, a tubular cross head guidebetween said cylinders, axially allined therewith and joined thereto, one side of said guide having a relatively short longitudinal. slot between its ends and an outstanding lug at one of said ends, the opposite side of said guide being formed with a relatively long longitudinal slot a cross head within said tubular guide consisting of a cylindrical side wall slidably contacting with said guide and having opposed longitudinal slots registering with thethe aforesaid tubular cross head guide havi ing transversely alined openings, a lever passing through the aforesaid registering slots and between said webs, a pivot bolt passing through the lever and the web openings, said bolt being accessible through the openings of aforesaid side wall and guide, a longitudinally disposed link pivoted at one end to one end of said lever and pivoted at its other end to the aforesaid lug, and pistons in the tWo cylinders having rods secured in the openings of the above-named bosses.

3. In a fluid-controlled mechanism, two

opposed cylinders having openings in their outer ends and screw plugs normally closing said openings, rigidly connected pistons in.

said cylinders, and means insertible through said openings into contact with both plstons, upon removal of said plugs, to lock said pistons against movement in either direction in case of emergency.

4, In a fluid-controlled mechanism, two opposed cylinders having openings in their outer ends and screw plugs normally closing said openings, rigidly connected pistons in said cylinders, and two screws insertible.

through said openings into contact with both pistons, uponremoval of said plugs, to lock said pistons againstmovement in either direction in case of emergency. 7

5. In a fluid controlled mechanism, a cylinder and piston assembly, the heads of the cylinder-portion of said assembly being provided with openings, removable means normally closing said openings, andmeans insertible through said openings into contact with the piston portion of said assembly upon removal of said closing'means, to lock said piston portion against movement in either direction in case'of emergency.

In testimony whereof We have hereunto affixed our signatures.

ROBERT L. DOOLITTLE.

WILLIAM C. HUNTER. 

